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Dynamic mechanical properties,deformation and damage mechanisms of eutectic high-entropy alloy AlCoCrFeni_(2.1)under plate impact

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Journal of Materials science & Technology 2023年第3期134卷 178-188页

作者： s.P.Zhao Z.D.Feng L.X.Li X.J.Zhao L.Lu s.Chen n.B.Zhang Y.Cai s.n.luo The Peac Institute of Multiscale sciences ChengduChina Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengduChina

shock compression and spallation of a eutectic high-entropy alloy(HEA)AlCoCrFeni_(2.1)with lamellar structure are investigated via plate impact loading with free-surface velocity *** as-cast and postmortem samples are characterized with transmission electron microscopy,electron back-scatter diffraction and scanning electron *** accurate Hugoniot equation of state is ***-ter shock compression to∼12 GPa,both the L1_(2)and B_(2)phases retain their ordered *** dislocations in the{111}slip planes,stacking faults and deformation twins are found in the L1_(2)phase,along with fewer dislocations in the{110}slip bands in the B(2)***-induced deformation twin-ning within the L1_(2)phase of this HEA is observed as a new deformation mechanism under various load-ing *** spallation,both ductile and brittle damage modes are *** micro voids and cracks prefer to nucleate at the phase boundaries chiefly,then in the B(2)*** similar shock stress,the spall strength of AlCoCrFeni_(2.1)HEA is about 40%higher than those of other reported dual-phase HEAs due to the high stability of its semi-coherent phase boundaries.

关键词： High-entropy alloy Hugoniot spall damage Microstructure

shock compression and spallation damage of high-entropy alloy Al_(0.1)CoCrFeni

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Journal of Materials science & Technology 2022年第33期128卷 1-9页

作者： n.B.Zhang J.Xu Z.D.Feng Y.F.sun J.Y.Huang X.J.Zhao X.H.Yao s.Chen L.Lu s.n.luo Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China The Peac Institute of Multiscale sciences Chengdu 610031China Department of Engineering Mechanics South China University of TechnologyGuangzhou 510641China

shock compression and spallation damage of a face-center cubic phase high-entropy alloy(HEA)Al_(0.1)CoCrFeni were investigated via plate impact experiments along with free surface velocity *** samples were characterized with transmission electron microscopy and electron backscatter *** Hugoniot equation of state and spall strength at different impact strengths were *** exists a power-law relation between spall strength and strain *** spall strength of Al_(0.1)CoCrFeni HEA is about 50%higher than those of previously studied HEAs and comparable to those widely applied structural stainless steels at the same shock *** glide and stacking faults are the important deformation mechanisms in the Al_(0.1)CoCrFeni *** are only observed at high shock *** in the Al_(0.1)CoCrFeni HEA is ductile in *** are nucleated preferentially in grain interiors,and the intragranular voids show a strong dependence on grain boundary misorientation and peak stress.

关键词： Al_(0.1)CoCrFeni High-entropy alloy Hugoniot spall damage Microstructure

Multiple ballistic impacts on 2024-T4 aluminum alloy by spheres:Experiments and modelling

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Journal of Materials science & Technology 2021年第35期94卷 164-174页

作者： J.C.Cheng s.P.Zhao D.Fan H.W.Chai s.J.Ye C.Li s.n.luo Y.Cai J.Y.Huang school of Materials science and Engineering Southwest Jiaotong UniversityChengduSichuanP.R.China The Peac Institute of Multiscale sciences ChengduSichuanP.R.China

Multiple ballistic impacts are carried out on a 2024-T4 aluminum alloy by spherical steel projectiles(5-mm diameter)at~400 m s^(-1),to investigate its dynamic deformation and *** ballistic impact process is captured with high-speed *** samples are characterized with optical imaging,three-dimensional laser scanning,microhardness testing and electron backscatter *** increasing number of impacts,crater diameter increases slightly,but crater depth and crater volume increase significantly,and strain accumulation leads to microhardness increase *** parameters all follow power-law relations with the number of ***-like deformation bands and macroscopic deformation twins are produced by impact as a result of spontaneous dislocation self-pinning under high strain rate,large shear *** multiple impacts,shear strain accumulation in the arc-shaped region of the crater induces deformation twinning when it exceeds a critical value(~1.1-1.6).It is highly possible that the deformation twins are related to deformation bands,since they both share one set of the{111}pole with the initial matrix grain.A finite element method model is optimized to reproduce experimental observations and interpret deformation mechanisms.

关键词： 2024Al-T4 alloy Multiple impacts Twin-like deformation band Deformation twinning Finite element method

Effect of rotationally accelerated shot peening on the microstructure and mechanical behavior of a metastableβtitanium alloy

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Journal of Materials science & Technology 2021年第16期75卷 27-38页

作者： Xinkai Ma Zhuo Chen Dongling Zhong snluo Lei Xiao Wenjie Lu shanglin Zhang Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China state Key Laboratory of solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China national Key Laboratory of Reactor system Design Technology Nuclear Power Institute of ChinaChengdu 610041China

Microstructural evolution and deformation mechanism of a metastableβalloy(Ti-10 V-2 Fe-3 Al)processed by rotationally accelerated shot peening(RAsP)were systematically investigated with optical microscopy,X-ray diffraction,electron backscatter diffraction and transmission electron *** gradient hierarchical microstructures(gradients inα″martensite andβphase,and hierarchical twins range from the nanoscale to microscale)can be fabricated by RAsP via changing the shot peening *** hardening behavior and tensile mechanical properties of gradient hierarchical microstructure were systematically *** deformation twinning systems of{112}α″and{130}α″in the kinkedα″martensite were revealed during the tensile *** was found that stress-induced martensitic transformation,twinnedα″martensite and the related dynamic grain refinement contribute to hardness and work hardening *** improvement of strength and ductility of the metastableα″titanium alloy can be achieved by introducing a gradient hierarchical microstructure.

关键词： Titanium alloys Gradient hierarchical microstructure α″martensite Rotationally accelerated shot peening Mechanical behavior

Large language model and domain-specific model collaboration for smart education

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Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 333-341页

作者： Yawei luo Yi YAnG school of software Technology Zhejiang UniversityNingbo 315048China College of Computer science and Technology Zhejiang UniversityHangzhou 310027China

In this paper,we introduce the large language model and domain-specific model collaboration(LDMC)framework designed to enhance smart *** LDMC framework leverages the comprehensive and versatile knowledge of large domain-general models,combines it with the specialized and disciplinary knowledge from small domainspecific models(DsMs),and incorporates pedagogy knowledge from learning theory *** integration yields multiple knowledge representations,fostering personalized and adaptive educational *** explore various applications of the LDMC framework in the context of smart education.

关键词： smart language knowledge

switching Behavior of Cascode Gan Under Influence of Gate Driver

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CsEE Journal of Power and Energy systems 2024年第4期10卷 1816-1833页

作者： Bin luo Guangzhao luo sihai Li school of Automation Northwestern Polytechnical UniversityXi’an 710072China

With high-frequency,low power dissipation and high-efficiency characteristics,Gallium nitride(Gan)power devices are of significant benefit in designing high-speed motor drives,as they improve performance and reduce ***,due to the cascode structure,coupling with the parasitics in gate driver and power circuits,power converters based on cascode Gan are prone to overshoot and oscillate on switching waveforms,which may lead to serious EMC problems,or even device *** complicated structure of cascode Gan device makes the gate driver design comparatively *** analytical model of the switching process considering gate driver parameters is proposed in this *** influence of gate driver parameters on switching behavior is investigated from the perspective of switching speed,waveform overshoot,and power ***-offs among overshoot,switching speed,and power loss are discussed;guidelines to design gate driver parameters are given.

关键词： Gallium nitride(Gan) gate driver oscillation and overshoot switching characteristics

Dynamic and electrical responses of a curved sandwich beam with glass reinforced laminate layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 155-178页

作者： n.sHAHVEIsI s.FELI Department of Mechanical Engineering Razi UniversityKermanshah ***Iran

The dynamic responses and generated voltage in a curved sandwich beam with glass reinforced laminate(GRL)layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact(LVI)are *** current study aims to carry out a dynamic analysis on the sandwich beam when the impactor hits the top face sheet with an initial *** the layer analysis,the high-order shear deformation theory(HsDT)and Frostig's second model for the displacement fields of the core layer are *** classical non-adhesive elastic contact theory and Hunter's principle are used to calculate the dynamic responses in terms of *** order to validate the analytical method,the outcomes of the current investigation are compared with those gained by the experimental tests carried out by other researchers for a rectangular composite plate subject to the *** element(FE)simulations are conducted by means of the ABAQUs *** effects of the parameters such as foam modulus,layer material,fiber angle,impactor mass,and its velocity on the generated voltage are reviewed.

关键词： analytical model piezoelectric layer curved sandwich beam glass reinforced laminate(GRL) pliable core low-velocity impact(LVI) classical non-adhesive elastic contact theory

Catalyst design and structure control for photocatalytic refineries of cellulosic biomass to fuels and chemicals

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Journal of Energy Chemistry 2024年第7期94卷 102-127页

作者： Lulu sun nengchao luo state Key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Lignocellulosic biomass is the largest renewable hydrocarbon resource on *** cellulose,one of the major components of lignocellulose,powered by solar energy is a promising way of providing lowcarbon-footprint energy chemicals such as H_(2),HCOOH,CO,and transportation ***-of-the-art biorefineries target the full use of biomass feedstocks as they have a maximum collection radius of 75-100 km,requesting efficient and selective photocatalysts that significantly influence the outcome of photocatalytic ***-performed photocatalysts can harvest a broad solar spectrum and are active in breaking the chemical bonds of cellulose,decreasing the capital investments of ***,photocatalysts should control the selectivity of cellulose conversion,originating target products to level down separation *** separation in photocatalysts and interfacial charge transfer between photocatalysts and cellulose affect the activity and selectivity of cellulose refineries to H2 and carbonaceous *** account for the challenges above,this review summarizes photocatalysts for the refineries of cellulose and downstream platform molecules based on the types of products,with the structure features of different types of photocatalysts discussed in relation to the targets of either improving the activity or product *** addition,this review also sheds light on the methods for designing and regulating photocatalyst structures to facilitate photocatalytic refineries of cellulose and platform molecules,meanwhile summarizing proposed future research challenges and opportunities for designing efficient photocatalysts.

关键词： Photocatalysts Biorefineries Cellulose Fuels Hydrogen

Precision regulation of plant aromatic amino acid homeostasis

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science China(Life sciences) 2024年第6期67卷 1316-1317页

作者： Jie luo Yazhouwan national Laboratory(YnL) Sanya 572025China school of Breeding and Multiplication(sanya Institute of Breeding and Multiplication) Hainan UniversitySanya 572025China

The aromatic amino acids(AAAs)phenylalanine(Phe),tyrosine(Tyr),and tryptophan(Trp)are not only building blocks of proteins,but also precursors of numerous primary and specialized metabolites(schenck and Maeda,2018).For instance,Trp is a precursor of the phytohormone auxin and the plant defense compounds indole glucosinolates,while Phe serves as a precursor of lignin,coumarin and *** plant natural products such as morphine and vitamin E are derived from Tyr,and have been employed in human medicine and nutrition(schenck and Maeda,2018;Wu et al.,2022;Yokoyama et al.,2021).

关键词： aromatic instance coumarin

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